From wildfires, particulates from cars, dry or humid air, and good old pollen, there are a lot of possible factors that affect outdoor air quality.
While being indoors protects you from the most intense air quality problems, some of the air still gets in and can recirculate over and over, affecting your indoor comfort and health. Being indoors also introduces different challenges and factors in air quality.
How Outside Air Matters Indoors
Most people assume air quality problems come from inside the home: dust, pet dander, or maybe an old carpet. But in reality, a surprising amount of what you’re breathing indoors started outside. The U.S. Environmental Protection Agency estimates that indoor air can be two to five times more polluted than outdoor air, not because outdoor air is “bad,” but because modern homes are very good at trapping air once it enters.
Every time you open a door or window, run an exhaust fan, start your dryer, or even just use your HVAC system, outdoor air is pulled into the home and circulated through the living spaces. In older Hudson Valley and Catskills homes, natural gaps in the building envelope can let outside air slip in continuously, especially during windy or humid weather. Newer, tightly sealed homes have the opposite problem: they keep stale indoor air and outdoor pollutants sealed inside unless the home is actively ventilated.
In both cases, the result is the same: outdoor air becomes indoor air, and whatever it carries, such as pollen, smoke, humidity, or pollutants, comes with it. That means the quality of the air outside your walls directly affects the comfort, health, and indoor environment of your home. And that’s where modern indoor air quality systems make a difference: they help you control what comes in, what stays out, and what gets filtered before you breathe it.
What’s Actually in the Outdoor Air in the Hudson Valley and Catskills?
When people think about “bad air,” they picture big cities or industrial zones, but the Hudson Valley and Catskills have their own set of outdoor air quality challenges that show up inside our homes in surprising ways. Different seasons bring different contaminants, and each affects comfort, health, and HVAC performance.
According to regional air quality monitors, in the representative City of Kingston in Ulster county, street-level air quality is cleaner than what the EPA recommends, but sometimes exceeds the World Health Organization standards.
Here are the most common outdoor factors that make their way indoors in our region:
Seasonal Pollen (Spring & Fall)
From late March through June and again in September through early November, trees, grasses, and ragweed release large amounts of pollen. Because most Hudson Valley homes rely on natural ventilation at least part of the year, pollen easily enters through:
- Open windows
- Window AC units
- Screen doors
- Attics and crawlspaces
- Air leaks around framing
- Indoors, pollen becomes a major trigger for allergies, sneezing, itchy eyes, and asthma flare-ups.
Wildfire & Wood Smoke (Summer & Winter)
While the Catskills don’t have large wildfires annually, we do experience smoke from:
- Canadian wildfires (recent summers)
- Western US wildfire smoke events drifting east
- Local outdoor burning
- Widespread wood stove usage in winter
Smoke particulates are extremely small (PM2.5 and smaller), meaning they bypass standard filters and linger in living spaces long after the event.
Wood Stoves & Winter Inversion Layers
As we found in a previous blog post, especially in Greene County, wood stoves are a primary or secondary heat source. On cold, still winter days, temperature inversions trap smoke close to the ground. Even homes that don’t burn wood can experience infiltration through walls, attics, and basements.
Common indoor symptoms include:
- “Campfire” smell indoors
- Headaches or scratchy throat
- Increased dust-like residue on surfaces
Traffic & Transportation Corridors
While most of the region is rural, major roadways still influence local air:
- I-87 corridor (Kingston → Catskill → Coxsackie)
- Route 9W corridor (Saugerties → Catskill → Hudson)
These areas experience higher levels of vehicle emissions and particulates. Homes close to these corridors often see finer dust accumulation indoors and higher particulate readings.
Humidity & Moisture
- Humidity isn’t always framed as “air pollution,” but it’s one of the largest outdoor influences on indoor air health in the Hudson Valley.
- Summer humidity enters through:
- Foundations and basements
- Attics and roof assemblies
- Open windows
- Air leaks in older framing
Once inside, high humidity supports mold, dust mites, musty odors, and general discomfort.
On the flip side, very dry winter air (especially during heating season) leads to:
- Dry skin
- Nosebleeds
- Static electricity
- Increased susceptibility to colds
Mold & Spores
Heavily wooded areas, and the forest floor itself release mold spores, especially after rain. Towns surrounded by mountains and dense tree canopy see higher spore counts that can infiltrate through building envelopes.
This is common in:
- Mountain valleys (Windham, Hunter, Tannersville)
- River towns with high moisture (Catskill, Saugerties, Hudson)
- Historic homes with basements and crawlspaces
Odors & VOCs
Outdoor sources also contribute less obvious pollutants like:
- Agricultural sprays (rural areas)
- Fuel/oil odors from heating systems
- Local industry or quarry dust in certain pockets
- Asphalt & roofing VOCs in the summer
While not always harmful, these odors and vapors often linger indoors without proper ventilation.
How Outdoor Air Gets Into Your Home
If you have an older home, you might be susceptible to air leaks and envelopes, attic and basement air pathways, and open building cavities that let air in.
In a newer home, you might be vulnerable to air coming in through exhausts, or suffering from “stale air” that isn’t being recirculated.
You may notice the side effects of this through symptoms like allergy flareups, musty basements in the summer, a smoky smell in the winter, dry air and nosebleeds in the winter, or fogged windows and condensation.
How Air Quality Systems Address These Issues
One of the solutions we offer are whole-house air cleaners, which absorb and eliminate airborne pollutants. The cleaners are installed directly into your HVAC system and provide protection against dust, smoke, pet dander and particulates.
If your problem is too much dry air, especially in the winter, a whole-house humidification system can get the right amount of moisture into the air. This is good for both your health and your home, as wood floors and furniture can crack if your home is too dry.
Why This Matters More in 2026 Than It Did 10 Years Ago
There has been an increase in the number of major wildfire smoke events, bringing massive amounts of smoke from far away. For newer buildings, there are tighter building codes which leads to less natural ventilation. And the rise of remote work, especially in the Hudson Valley, has made people experience the air quality in their home a lot more.
Not sure what’s affecting your indoor air? Give us a call at (845) 399-0669 to schedule a free consultation, or contact us.
